1. Field of the Invention
The present invention is directed to a battery charger for an electric appliance powered by an incorporated rechargeable battery such as an electric shaver or electric toothbrush, etc., and in particular to a water-resistant battery charger for charging the rechargeable battery of the electric appliance under a wet conditions.
2. Description of the Prior Art
In the past, since a water-resistant electric appliance powered by an incorporated rechargeable battery such as an electric shaver or electric toothbrush, etc., is often charged under wet conditions by a battery charger, the battery charger is also required to have water-resistant properties for safe charging operation under wet conditions. For example, a proposed battery charger 1F is illustrated in FIG. 20. The battery charger 1F comprises a casing 10F having a bottom opening 11F adopted to incorporate a charger circuit (not shown) therein, a bottom cover 50F for covering the bottom opening 11F, and a top cover 100F having horizontal and vertical portions 101F and 102F for hiding charging terminals 40F and lead wires 90F extending from the charger circuit to the charging terminals 40F along an outer surface of the casing 10F. After the charger circuit is incorporated in the casing 10F, and an electrically insulating resin is poured into the casing 10F, the bottom opening 11F is covered with the bottom cover 50F. The top cover 100F also has a connector 103F projecting from the horizontal portion 101F for engaging to a recess formed in the electric appliance. When the connector 103F of the battery charger 1F is inserted into the recess, charging terminal pins of the electric appliance disposed in the recess are connected with the charging terminals 40F through terminal holes 104F formed in the connector 103F, so that a charge current is supplied to the rechargeable battery of the electrical appliance.
Therefore, the battery charger 1F of the prior art is characterized by a complex structure including the charger circuit incorporated in the casing 10F, the charging terminals 40F and lead wires 90F exposed on the exterior surface of the casing 10F, and the top cover 100F for hiding and protecting the terminals 40F and lead wires 90F between the top cover 100F and the casing 10F. Such a complex structure would create difficulties in fabricating a small-sized battery charger and thus expensive production cost.